Halogenated acyl hydroquinone derivative developers



United States Patent 3,246,988 HALOGENATED ACYL HYDRDQUINONE DERIVATIVE DEVELOPERS Ralph F. Porter and Thomas E. Gompf, Rochester, N.Y., assignors to Eastman Kodak Company, Rochester, N.Y., a corporation of New Jersey N0 Drawing. Filed May 8, 1964, Ser. N 366,127 14 Claims. (Cl. 96-66) This application is continuation-in-part of our application Serial No. 183,354, filed March 29, 1962, now abandoned.

The present invention relates to photographic materials, and to a method of photographic development. More particularly, the present invention relates to developerincorporated photographic materials and to a method of processing and using the same.

In the usual process of photographic development, the exposed photographic element comprising a support having at least one gelatino-silvenhalide emulsion layer thereon, is immersed in a developing bath containing a silver halide photographic developing agent. The developing bath is normally maintained as a separate processing bath and with continuous use, the bath usually becomes less efiicient so that special techniques and replenishments are normally required to maintain optimum processing efi'iciency. The developing baths of the prior art normally contain a developing agent, a preservative, such as sodium sulfite, and alkali to activate the developing agent, and may also contain other materials, such as sodium bromide (restrainer), antifoggants, etc. The present invention relates to a Way to eliminate the usual type of developing bath, and quite unexpectedly obtains optimum results by incorporating certain photographic developing agent-precursors in emulsion layers, or in adjacent layers, wherein the active developing agent is released by alkaline treatment of the layers after exposure.

It is, therefore, an object to the present invention to provide certain developing agent-precursor substances for incorporation in silver halide photographic emulsion layers, or layers adjacent thereto. Another object is to provide silver halide photographic materials which have said precursor substances incorporated in said emulsion layers, or layers adjacent thereto. A further object is to provide processing solutions for the development of said amulsion layers. Still another object is to provide a method of processing the emulsion layers of the invention.

The above objects are accomplished by incorporating certain acyl compounds in silver halide emulsion layers, or in layers contiguous thereto and, after photographic exposure, treating such layers with an alkaline solution, such as aqueous sodium carbonate, to release an active developing agent. The acyl compounds of our invention comprise halogenated acyl derivatives of a 1,4- dihydroxy benzene. The benzene ring of the 1,4-dihydroxy benzene compounds can contain any of the conventional substituents, such as alkyl (e.g., methyl, ethyl, t-buty], n-heXyl, n-octyl, etc.), halogen (e.g., chlorine, bromine, etc.), alkoxyl (e.g., methoxyl, ethoxyl, etc.), etc. Typical halogenated acyl compounds of our invention (which may or may not have the aforementioned substituents on the benzene rings thereof) include for example:

3,245,988 Patented Apr. 19, 1966 wherein R represents a haloakyl group (for example a haloalkyl group containing from about 1 to 3 carbon atoms, such as chloromethyl, dichloromethyl, trichloromethyl, ,B-chloroethyl, B-dichloroethyl, fi-trichloroethyl, bromomethyl, fiuoromethyl, difiuoromethyl, trifiuoromethyl, etc.), and R represents a hydroxyl group or a OOC-R group, wherein R has the values given above.

The developer precursor compounds of our invention can be incorporated in an ordinary photographic silver halide emulsion, or colloidal dispersion of a waterpermeable hydrophilic colloid suitable for preparing an undercoat or an overcoat for such silver halide emulsion, by mixing a solution or dispersion of the precursor com pound with the silver halide emulsion, or dispersion of hydrophilic colloid, prior to coating. For example, a developer precursor can be made up as an oil dispersion by stirring a solution of 10 grams of the developing agent precursor into 40 grams of Warm tricresyl phosphate, and then mixing this solution with grams 01 a 10 percent aqueous gelatin solution containing 10 cc. of a 5 percent aqueous solution of an alkylnaphthylene sodium sulfonate wetting agent. The resulting dispersion can then be homogenized by passing for 5 times through a colloid mill to produce a homogeneous colloid dispersion. Solvents other than tricresyl phosphate can be employed, including any of the crystalloidal compounds described in Jelley and Vittuin US. Patent 2,322,027, issued June 15, 1943. The resulting colloidal dispersion can then be added to an ordinary silver halide emulsion, or a dispersion of a water-permeable hydrophilic colloid, adapted for preparation of an undercoat or overcoat for such silver halide emulsion.

Instead of adding the oil dispersion directly to the liquid silver halide emulsion or colloidal dispersion, it can be dried for storage purposes and then be reconstituted for use by merely mixing with water.

The developing agent precursors of our invention can be adapted for addition to a liquid silver halide emulsion or colloidal dispersion by other means as well. Suitable methods will depend largely upon the solubility characteristics, particularly in water or polar soivents, of the particular precursors in question. For example, a 1:1 aqueous methanol solution of p-chloroacetoxyphenol can be prepared easily, while less water-soluble material can be dissolved or dispersed more easily in a phenolic solvent, or as an oil dispersion as described above.

After addition of the dispersion or solution of the developing agent precursor substance to the liquid emulsion or colloidal dispersion, the mixture is stirred to assure uniform results, or passed through a blending device, such as a colloid mill or Waring Blendor. A uniform coating can then be made on a suitable support and the coating dried. Suitable supports comprise any of the well known supporting materials, such as cellulose ester film (e.g., cellulose acetate, cellulose nitrate, cellulose acetate butyrate, cellulose acetate propionate, etc.), polyethylene, polypropylene polystyrene, polyethylene terephthalate and other polyesters, paper, polycarbonates, etc.

The photographic elements of our invention comprising a photographic development precursor either in the photographic silver halide emulsion layer, or layer contiguous thereto or both can then be exposed to an original or negative and developed by merely treating the exposed emulsion layer with an alkaline activator bath. Typical activator baths comprise, for example, an aqueous solution of an alkaline material, such as sodium carbonate, sodium hydroxide potassium carbonate, potassium hydroxide mixtures of sodium hydroxide and sodium sulfite, etc. Suitable baths can comprise, for example, an aqueous solution containing about 1 percent sodium hydroxide and percent sodium sulfite. A bath of the latter type is quite suitable for developing an exposed emulsion layer in about 30 seconds when the activator bath is at about 68 F. Modifications can easily be made in the activator baths without departing from the spirit and scope of the invention. For example an aqueous solution comprising about 4 percent of sodium carbonate and 5 percent of sodium sulfite produces development in about 30 seconds at 68 F. Another aqueous activator solution comprising 2 percent sodium hydroxide and 5 percent sodium sulfite produces useful photographic images in a few seconds when heated at 130 F. Particularly useful activator solutions have a pH of at least about 9.0 and preferably of at least about 10.5.

The activator solutions of the present invention can be applied to an exposed photographic element in any number of known ways such as by dipping, spraying or other suitable surface applications. If desired, a thickener can be added to the activator solution to increase the viscosity of the composition and make it more adaptable for continuous processing. Viscous compositions can then be removed by squeegeeing or water spraying. The photographic element can then be stabilized by conventional fixation or stabilization, such as by sodium thiosulfate.

The concentration of the halogenated acyl compounds used in our invention will vary, depending upon the particular chemical compound involved and the location of the compound within the photographic element. That is, if the halogenated acyl compound is incorporated within the silver halide emulsion undergoing development, it may be desirable to use a somewhat different concentration than would be used if the acyl compound were incorporated in a layer contiguous to the photographic silver halide emulsion. A useful concentration of halogenated acyl compound for incorporation in the emulsion is from about 0.1 to 4.0 moles per mole of silver halide. A particularly useful range is from about 0.25 to 2.0 moles per mole of silver halide, with especially useful results being obtained within the range of about 0.4 to 1.0 mole per mole of silver halide. For incorporation in layer contiguous to the silver halide emulsion layer, somewhat larger concentrations of halogenated acyl compound can be, tolerated without adverse effects. A particularly useful effect of our invention is that even when incorporated within the silver halide emulsion, the halogenated acyl compounds of Formula I have little or no desensitizing effects. In many cases, this is not true where developing agents, per se, are incorporated within the silver halide emulsion layers.

Photographic silver halide emulsions useful in our invention comprise any of the ordinarily employed silver halide developing out emulsions, such as, silver-chloride, -chlorobromide, -chloroiodide, -chlorobromoiodide, -bromide and -bromoiodide developing-out emulsions. Any of the conventionally employed water-permeable hydrophilic colloids can be employed in the silver halide emulsions, or in layer contiguous thereto. Typical water-permeable hydrophilic colloids include gelatin, albumin, polyvinyl alcohol, agar agar, sodium alginate, hydrolyzed cellulose esters, hydrophilic polyvinyl copolymers, etc.

Photographic silver halide emulsions useful in our in vention can also contain such addenda as chemical sensitizers, e.g., sulfur sensitizers (e.g., allyl thiocarbamate, thiourea, allyl isothiocyanate, cystine, etc.), various gold compounds (e.g., potassium chloroaurate, auric trichloride, etc.). (See U.S. Patents 2,540,085, 2,597,856 and 2,597,915), etc.

Photographic silver halide emulsions useful in our invention can also be sensitized by other means, such as by alkylene oxide polymers, many of which are well known to those skilled in the photographic art. Typical polyalkylene oxide polymers include those of U.S. Patents 2,423,549 and 2,441,389.

The emulsions of the invention can also contain speedincreasing compounds of the quaternary ammonium type as described in U.S. Patents 2,271,623, issued February 3, 1942; 2,288,226, issued June 30, 1942; 2,334,864, issued November 23, 1943; or the thiopolymers as described in Graham et al. U.S. application Serial No. 779,839, filed December 12, 1958, now Patent No. 3,046,129; and Dann et al. U.S. application Serial No. 779,874, filed December 12, 1958, now Patent No. 3,046,134.

The emulsions may also be chemically sensitized with reducing agents such as stannous salts (Carroll U.S. Patent 2,487,850), polyamines such as diethylene triamine (Lowe and Jones U.S. Patent 2,518,698), polyamines such as spermine (Lowe and Allen U.S. Patent 2,521,925), or bis-(B-aminoethyl) sulfide and its water-soluble salts (Lowe and Jones U.S. Patent 2,521,926).

The emulsions may also be stabilized with the mercury compounds of Allen, Byers and Murray U.S. application Serial No. 319,611; Carroll and Murray U.S. application Serial No. 319,612; and Leubner and Murray U.S. application Serial No. 319,613, all filed November 8, 1952, now U.S. Patents 2,728,663, 2,728,664 and 2,728,665,

. respectively, granted December 27, 19.55.

The addenda which we have described may be used in various kinds of photographic emulsions. In addition to being useful in X-ray and other nonoptically sensitized emulsions, they may also be used in orthochromatic, panchromatic, and infrared sensitive emulsions. They may be added to the emulsion before or after any sensitizing dyes which are used. The agents may be used in emulsions intended for color photography, for example, emulsions containing color-forming couplers or emulsions to be developed by solutions containing couplers or other color-generating materials, emulsions of the mixed-packet type, such as described in Godowsky U.S. Patent 2,698,- 794, issued January 9, 1955; or emulsions of the mixedgrain type, such as described in Carroll and Hanson U.S. Patent 2,592,243.

It has been found that the development rate of the compounds represented by Formula I above sometimes can be improved by adding an auxiliary developing agent either to the silver halide emulsion layer, or a hydrophilic layer contiguous thereto, or in the activator bath. Typical auxiliary developing agents include those described in the copending application Serial No. 134,014, filed August 5, 1961, now abandoned, of P. H. Stewart, G. E. F-allesen and J. W. Reeves, Jr. Typical auxiliary developing agents described in this application include 3-pyrazolidone compounds containing an alkyl (e.g., methyl, ethyl, etc.) or aryl substituent (e.g., phenyl, ptolyl, etc.). In addition, such 3-pyrazolidones can be made inert to facilitate incorporation in the emulsion by introducing an acyl or acyloxy substituent which will be hydrolyzed from the compound by treatment with the above activator solutions to produce the desired developing agent. Typical auxiliary developing agents include, for example, 1-phenyl-3-pyrazolidone, 1-p-tolyl-3-pyrazolidone, 1-phenyl-5-methyl-3-pyrazolidone, l-acetamidophenyl-3-pyrazolidone, 1-phenyl-4,4-dimethyl-3-pyrazolidone, 1-phenyl-4-methyl-3pyrazolidone, etc. Typical inert precursors useful for incorporation include 3-acetoxy- 1-phenyl-3-pyrazolidone (Enol ester), Z-(pyridinium acetyl)-1-phenyl 3 pyrazolidone chloride, 1-phenyl-2-benzoyl-3-pyrazolidone, l-phenyl-2-lauroyl 3 pyrazolidone, 1-phenyl-2-chloroacetyl-3-pyrazolidone, etc.

The concentration of auxiliary developing agents can be varied and, of course, no auxiliary developing agent need be employed unless so desired. Usful concentrations of auxiliary developing agents vary from about 0.01 mole to 2.0 moles per mole of acyl compound. Depending upon the particular auxiliary developing agent employed, larger or smaller quantities can be used.

One of the advantages of the development precursors of the present invention is that they can be used alone without any auxiliary developing agent and yet provide quite useful photographic results. While such auxiliary developing agents will, in some instances, make the resulting photographic element more rapidly developable, the developer precursors of our invention are quite effective in the absence of such auxiliary developing agents.

The halogenated acyl compounds of Formula I above, wherein R represents a halogenated acyloxy radical, can be'prepared by esterification of the corresponding hydroquinone. compound (nuclear substituted or unsubstituted). Esterification can be accomplished by merely heating together the hydroquinone compound and an organic acid, anhydride, or halide. Av basic condensation catalyst can be employed, if desired. Where an acid or anhydride is used' for the esterification, improved yields and shorter reaction times can be accomplished by use of an azeotropic agent, such as toluene, benzene, etc. Organic amine hydrohalide activators are particularly useful where an organic acid halide is employed. The monoesters of Formula I above can be prepared by first esterifying a monobenzyl ether of a hydroquinone compound, followed by hydrogenolysis of theether-ester'so produced. Any of the ordinarily employed hydrogenation reactions can be employed, although we have found that particuly useful results can be obtained by the use of palladium on charcoal catalyst plus hydrogen gas. Other hydrogenation catalysts, such as Raney nickel, etc., can be employed to advantage.

The following examples will serve to illustrate the preparation of typical acyl compounds or intermediates useful in our invention.

Example 1 1,4-bis(chloroacetoxy)benzene suitable for incorporating in an emulsion layer according to the invention was prepared by adding dropwise 51 g. of chloroacetyl chloride to a suspension of hydroquinone comprising 22.02 g. of hydroquinone in 900 ml. of benzene and containing 36 ml. of pyridine. The mixture was stirred and maintained at 510 C. and stored at C. for about 6 hours after the addition was complete. The solids formed by the reaction were collected by suction filtration and washed with several portions of benzene. The filter cake was then washed with 200 ml. of water and dried in vacuum over calcium chloride for 48 hours. 37.09 g. of white plates having a melting point of 125-129 C. were crystallized from a solution comprising 250 ml. of chloroform' and 100 ml. of ligroin.

Analytical calculation for C H O Cl C, 45.7; H, 3.06; Cl, 27.0. Found: C, 45.6; H, 3.1; Cl, 27.0.

Example 2 1,4-bis(dich1oroacetoxy)benzene suitable for incorporating in a photographic emulsion as a developing agent precursors according to the invention was prepared by adding dropwise over a 2-hour period 32.4 g. of dichloroacetyl chloride to a suspension of hydroquinone comprising 11.01 g. of hydroquinone in 250 ml. anhydrous benzene and containing 18 ml. of pyridine. The mixture was stirred and maintained at 510 C. after addition was complete. The mixture was then stirred at 10 C. overnight. The solids were collected by suction filtration and washed with several portions of benzene and followed by several portions of water. Drying in air yielded 29 g. of a solid having a melting point of 130-131.5 C. The solid" was then crystallized from 150 ml. of benzene to give 24.75 g. of white plates having a melting point of 130-132 C.

Analytical calculation for C H O Cl C, 36.2; H, 1.82; Cl, 42.7. Found: C, 36.6; H, 2.0; Cl, 42.2.

Example 3 1,4 bis(trichloroacetoxy)benzene suitable for incorporating in an emulsion layer as a developing agent precursor of the invention was prepared by adding 22.02 g.

Example 4 1-benzyloxy-4-chloroacetoxybenzene for use in the present invention as an intermediate was prepared by adding 29 g. chloroacetyl chloride dropwise over a 30-minute interval to a solution comprising 40 g. of p-(benzyloxy) phenol and 18 ml. of pyridine in 500 ml. of anhydrous benzene. The solution was then stirred and maintained at approximately 10 C. for about 30 minutes and then stored overnight at 10 C. The next morning the solids were collected by suction filtration and washed with two 50 ml. portions of ligroin. and two 150 ml. portions of water. By drying in vacuo over calcium chloride, "18 g. of a tan solid was obtained.

The filtration was washed with two ml. portions of water and evaporated to dryness to give 47 g. of the tan solids. Repeated crystallization from ligroin yielded white flakes having a melting point of 102103.5 C.

Analytical calculation for C H O Cl: C, 65.0; H, 4.73; Cl, 12.87. Found: C, 65.9; H, 4.6; Cl, 13.1.

Example 5 p-(Chloroacetoxy) phenol of the invention was prepared by catalytically reducing 13.83 g. of 1-benzyloxy-4- chloroacetoxy-benzene in 50 ml. of anhydrous tetrahydrofuran in the presence of 1 g. of 10 percent palladium-onch arcoal at 60 C. and 50 psi. of hydrogen. Reduction was complete in two hours after which dia-tomaceous earth filter aid was added and the solids removed by suction filtration. Evaporation of the solvent gave a white solid having .a melting point of about 105111 C. Repeated crystallization from a ligroin-chloroform solution gave 5.79 g. of near white needles having a melting point of 111.5114 C.

Analytical calculation for C H O Cl: C, 51.5; H, 3.78; Cl, 19.01. Found: C, 51.7; H, 4.1; Ci, 18.8.

Example 6 1benzyloxy-4-dichloroacetoxybenzene of the invention was prepared by adding dropwise 17.1 g. of dichloroacetyl chloride over a 15-minute period to a solution comprising 20.02 g. of p-(benzyloxy) phenol in 250 ml. of anhydrous benzene containing 8.7 g. of pyridine. The solution was then stirred and maintained at about 10 C. for a few minutes and then stored at 10 C. for about 3 days. After the storage period, the solids were collected by suction filtration and washed with several portions of water. Drying in air yielded 19 g. of a tan solid which was crystallized twice from benzene-ligroin to give white plates having a melting point of 116.51l8 C.

Analytical calculation for C H O Cl C, 58.0; H,

Found: C, 58.3; H, 3.9; Cl, 22.5.

Example 7 p-(Dichloroacetoxy)phenol of the invention was prepared by catalytically reducing 14 g. of 1'-benzy-loxy-4-dichloroacetoxybenzene in 100ml. of anhydrous tetnahydrofu-ran in the presence of 1 g. of 10 percent palladiumon-charcoal atroom temperature and 50 psi. hydrogen. The reduction was complete in about 4 hours after which a filter aid was added and the solids removed by suction filtration. Evaporation of the solvent yielded an oily white solid which was twice crystallized from a solution of chloroform-ligroin to give 6.45 g. of tan plates having a melting point of 76.578.5 C.

Analytical calculation for C H O Cl C, 43.5; H, 2.74; Cl, 32.1. Found: C, 44.1; 44.3; H, 2.6, 2.8.

7 Example 8 1+benzyloxy-4-trichloroacetoxybenzene was prepared by adding dropwise over a 1-hour interval 43 g. of trichloroacetylchloride to a solution containing 40.05 g. of p (.benzyloxy)phenol in 500 ml. of anhydrous benzene and containing 17.4 g. of pyridine. The solution was stirred and maintained at 5l0 C. during addition. After addition was completed, the mixture was allowed to stand at C. overnight after which the solids were removed by filtration and washed with several portions of benzene. Evaporation of the filtrate gave 65 g. of oily solid which was crystallized from a solution comprising 150 ml. of benzene and 100 ml. of ligr-oin to yield 37 g. of ten crystals having a melting point of 108110 C. An additional 19 g. of crystalline was contained by concentration of the first liquors.

1-benzyloxy-4-trichloroacetoxybenzene (6.90 g.) in anhydrous tetra'hydrofuran (50 ml.) was catalytioally reduced in the presence of palladium-on-charcoal (1.0 g. of 10%) at 60 C. and 50 p.s.i. hydrogen. Reduction completed in 75 minutes; Super-eel (diatomaceous earth) was added and the solids removed by suction filtration. Evaporation of the solvent yielded an oily white solid, which was twice crystallized from ligroin to give 1.60 g. of white flakes, M.P. 77-78 C. (mixed M.P. with p-(dichloroacetoxy)phenyl, 7579 C.)

Analytical calculation for C H O Cl C, 43.5; H, 2.74; Cl, 32.1; mol. wt. 221. Found: C, 44.3; H, 2.8; Ci, 30.6; mol. wt. 212, 216.

The following examples will serve to illustrate the useful effects of our development precursors when incorporated within an ordinary photographic silver halide emulsion. While these precursors can be dispersed directly in the emulsion, they can also be incorporated in the photophate as a solvent for the development agent precursors identified in the following table. As in Example 9, a -blank dispersion containing no development agent precursor was prepared to serve as a control. These melted dispersions were then added to an ordinary gelatino-silverbromiodide emulsion at a concentration of 0.5 mole of development agent precursor per mole of silver bromiodide. To the resulting aliquot portions of the bromiodide emulsion containing development agent precursors were added 10 grams of a 10% ethanol solution of 1-phenyl-3- pyrazolidone per mole of silver bromiodide, so that the emulsion contained one gram of this compound per mole of silver bromiodide. No 1-phenyl-3-pyrazolidone solution was added to the control, but a separate emulsion was used to which the blank dispersion had been added and to this emulsion was added the indicated amount of 3-pyrazolidone solution. The emulsion containing the blank dispersion and the emulsion containing the blank dispersion plus the l-phenyl-3-pyrazolidone serve as controls to illustrate the improvement obtained when the development agent precursors of our invention were added at the indicated concentration of 0.5 mole of development agent precursor per mole of silver bromiodide. The aliquot portions of emulsions were then separately coated on cellulose acetate film support, dried, exposed on an intensity scale sensitometer to tungsten illumination and developed for 30 seconds at 68 F. in an aqueous solution containing 1% sodium hydroxide and 5% sodium sulfite. The samples were then washed and fixed in the usual manner with sodium thiosulfate. The following sensitometric results were obtained, measurement of speed being made at a density level of 0.3 above fog. The development agent precursors are identified by preparative example numbers.

graphic element in a layer contiguous to the photographic silver halide emulsion layer.

Example 9 A number of oil dispersions in tricresyl phosphate (10 grams of developing agent precursor in grams of tricresyl phosphate) were prepared. A blank dispersion was also prepared in an identical manner to serve as a control. These dispersions were separately added to aliquot portions of an ordinary photognaphic gelatino-silverbromoiodide emulsion at a concentration of 0.5 mole per mole of silver halide. The dispersions were then coated separately on ordinary cellulose acetate photographic film, and the coatings air dried. The exposed emulsions were then developed by merely immersing them in an aqueous solution of sodium carbonate. While the emulsion containing the blank dispersion showed no visible image, an identical strip of emulsion containing the compound of Example 1 above showed an excellent reproduction of the step wedge element of the sensitometer.

Example 10 Several gelatin dispersions were prepared according to the above-described technique using Warm tricresyl phos- .tion of sodium carbonate monohydrate.

The halogenated development precurors of our invention have marked advantages over the unhalogenated analogues in that they provide much more rapid development of exposed photographic silver halide elements. This is illustrated in the following example.

Example 11 Photographic silver halide elements were prepared according to the techniques illustrated in Examples 9 and 10, using development precursors identified in the following table, these precursors being incorporated in the silver halide emulsions at a concentration of 0.5 mole per mole of silver halide. The silver halide emulsions used were all gelatino-silver-bromoiodide emulsions. Exposures were made as illustrated in Example 10 using a step wedge calibrated in increments of 0.15. After exposure of the film strips in an intensity scale sensitometer, they were processed for the indicated times in an aqueous 4% solu- The strips were then removed from the activator, rinsed, fixed with an ordinary hypo solution, washed and dried. The density of the fourth step on .eachstrip was then measured, the results'being those given in the following table:

"Whitmore and Mader, Canadian 'Patent 602,607, issued August 2, 1960. TheysmayalsoLbe.usedzinemulsions iu- TABLE B 4% Sodium Carbonate Coating Incorporated.hydroquiuoue derivative (Nfl2CO3'H20) No. :(0.5 mole/Ag mole) B1 .16 .16 17 B-2 Control plus .p-acetmryphenol- 54. 09 88 1. 33 B-3 Controlplus p-'(cliloroacetoxy)phono 73 92 1. 09 1. 32 B 4 Controlzpluslp-(dicliloroacetoxy)phenol. 68; 88 1. O9 1. 50 B-5 Control plus l,4ebis(acetoxy)benzene 1.16 .18 .20 .25 13-6. Control plus 1,4 bis(chloroacetoxymenzone-. 62 .84 1. 03 1.38 3-7 Control plus 1,4-bis(dicl11oroacetoxy)ben- .53 67 .85 1.08

zene. 13-8. Control plus 1,4-bis(trichloroacetoxymen 18 75- 1. 07: 1. 53

zene.

Example 12 In exactly the manner shown in Example 11, film strips of an ordinary gelatino-silver-bromoiodide emulsion were prepared and processed, except that an activator containing 2% sodium hydroxide and 5% sodium sulfite was used. The following results were obtained.

tended for :use in a monobath process such as described in Haist et al., US. Patent 2,875,048, issued February 24, 1959, and in web-type processes, such as the one described in Tregillus et al., Canadian Patent 664,377, issued June 4, 1963.

Of course, the activator solutions which are used in our TABLE Coating Incorporated Hydroguinone derivative (0.5 '1" 2 40 80 .160 320 .no. mole/Ag-mole o-1 Control (no addendum) .05 ..0s .07 .10 .13 .1162 .16 .18 .19 C4 Control plus p-aeetoxyphenoln .06. .10 .55, .98 1.61. 1:97 2. 29 2. 51 2.62 C- 1 Control plus p-(cliloroacetoxy) phenoL. .24 .37 .78 1.13 1. 68 2.01 2.37- 2. 69 2. 70 C-4 Control plus1,4-bis(acetoxy)benzene- .06 .09 .22 .48 .80 1.18 1.58 1, 96 2. 44 0-5 Control plus'1,4-bis(chloro-aeetoxy) Demo .12 .14 .48, .78: 1. 413 L74; 2. 21 2.53 2.70

It has .been foundfthat'thedevelopment precursor cominvention are stable for extended periods of .time andare pounds :of our invention are particularly useful in that not subject to the harmful decomposition reactions .so emulsions containing them are considerably more stable common to conventional photographic developing soluthan emulsions containingdeveloping cornpounds, .per se. 40 tions 'when these developing solutions are stored "for ex This advantage becomes particularly apparent uponincutended periods of time. No special precautions are rebation .at elevated temperatures for extended periods .of quired to prevent oxidation o'f the activator solutions since time. For example, hydroquinonehas theetfectof lowerthey are inherently quite-stable. If desired, the activator ing the speed of the emulsions, if it is incorporated 'within solutions can be incorporated in a carrier, such as gelatin the emulsion as an active developing agent. While the and coated in contact with the photographic silver halide disadvantages of using such incorporated developing emulsion layer which contains the development precursors agents can be mitigated somewhat by incorporating the of our invention. After exposure, the development can developing agent in a separate, contiguous layer, the debe effected merely by heating the photographic emulsion velopment precursors of the present invention make this layer to a temperature suflicient to release water, which step unnecessary. However, the development precursors may be present in.the supportor ina separatelayer in the of our invention can likewise be used to advantage by photographic elernent. This water thendissolves'theiactiincorporation in a layer contiguous to the emulsion layer. Vator solution from the hydrop'hilic colloid layers :and The developer precurors of our invention can be used takes it into the photographic silver halide-emulsion layer in emulsions intended for use .in diffusion transfer procwhlare-devebllment-is effectedesses which utilize the undeveloped silver halide in the Theelevated t mperatures from 'a'bOut'95-l50" C. are nonimage areas of the negative to form a positive by disusually sufficient tO-effCOt'dfiVfllopmel'ltlln 'thlS manner. If solving the undeveloped silver halide and precipitating it deslred, additional {moisture (111111 196 fladtid y p y n on a receiving layer in 105 proximity 10 the original steam upon thC SCHSIUVC surface Of the photographic .elesilverhalide emulsionlayer. Suchprocesses aredescribed mentin Rott, vU.S. Patent 2,352,014,:issued June 20, .1944, and The invention has been described In detail with particu- Land, s patents 4,029 issued January 29 1952; lar reference to preferred embodiments thereof, but it will 2,698,236, issued December 2g 1954 and 2 543 1 1 be understood that variations and modifications can be .issuedFebruary 27, 1951;.aud'Yackelet al.,;U S Pat 1; eifect ed within the splrlt and scope of the invention as 3,020,155, issued February 6 1962 They may also be descrlbed hereinabove and as defined 1n the appended used in color transfer processes which utilize the diffusion 5 transfer of an image wise distribution of developer, cou- We Clam: pler or dye, from a light-sensitive layer to a second layer, A l Q f p lem nt comprising a support and a while the two layers are in close proximity to one anphotogrfiphlc sllv-er hiflhde emulslon ay {111d Integral other. Color processes of this type are described in Land, 531d PhQtOgTaPhIC element a Y sllvel' Us Patents 2559643, issued July 10, 1951, and 2,698; halide developing agent precursor wherein at least one of 798, issued January 4, 1955; Land and Rogers, Belgian U19 PY Y groups of 531d hydroqulnone has 1366" patents 554 933 and 554 934 granted August 12 1957; esterified to form a hydrolyzable, halogenated aliphatic International Polaroid, Belgian Patents 554,212, granted Y Y radical- July 16, 1957, and 554,935, granted August 12, 1957; 2. A photographic element comprising a support and Yutzy, US. Patent 2,756,142, granted July 24, 1956, and aphotographic, water-permeable, hydrophilic, silver halide emulsion layer containing an acyl compound represented by the following general formula:

wherein R represents a haloalkyl group, and R represents a member selected from the class consisting of a hydroxyl group and a OOCR group, wherein R represents a haloalkyl group.

3. A photographic element comprising a paper support and a photographic silver halide emulsion layer, and integral with said photographic element a water-permeable, hydrophilic colloid layer containing (a) an acyl compound represented by the following general formula:

R2 wherein R represents a haloalkyl group and R represents a member selected from the class consisting of a hydroxyl group and a OOCR group, wherein R represents a haloalkyl group, and (b) a 3-pyrazolidone photographic developing agent.

4. A photographic element as defined in claim 3 wherein said 3-pyrazolidone is l-phenyl-3-pyrazolidone.

5. A photographic element comprising a flexible support and a photographic silver halide emulsion layer, and integral with said photographic element, a water-permeable, hydrophilic colloid containing an acyl compound selected from those represented by the following general formula:

I OH

wherein R represents a haloalkyl group.

6. A photographic element according to claim 5 wherein said acyl compound is p-chloroacetoxyphenol.

7. A photographic element comprising a flexible support and a photographic silver halide emulsion layer, and integral with said photographic element, a waterpermeable, hydrophilic colloid containing an acyl compound selected from those represented by the following general formula:

wherein R and R each represents a haloalkyl group.

8. A photographic element as defined in claim 7 Wherein said acyl compound is l,4-bis(trichloroacetoxy)benzene.

9. A photographic element as defined in claim 7 wherein said acyl compound is l,4-bis(dichloroacetoxy)benzene.

10. A photographic element as defined in claim 7 wherein said acyl compound is 1,4-bis(chloroacetoxy)benzene.

11. A photographic element comprising a support and a photographic silver halide emulsion layer, and integral with said photographic element, a colloidal dispersion of an acyl compound in a water-insoluble, water-permeable crystalloidal solvent, said acyl compound being represented by the following general formula:

wherein R represents a haloalkyl group and R represents a member selected from the class consisting of a hydroxyl group and a OOCR group, wherein R represents a haloalkyl group.

12. A photographic element according to claim 11 wherein said crystalloidal solvent is a high-boiling ester of a phenol.

13. A photographic element according to claim 12 wherein said high-boiling ester is tricresyl phosphate.

14. A process for forming a visible photographic image comprising developing a photoexposed photographic element comprising a support and a photographic silver halide emulsion layer, and integral with said photographic element, a waterpermeable, hydrophilic colloid layer containing an acyl compound represented by the following general formula:

wherein R represents a haloalkyl group and R represents a member selected from the class consisting of a hydroxyl group and a OOCR group, wherein R represents a haloalkyl group by imbibing throughout said photographic silver halide emulsion layer an aqueous alkaline solution containing sufficient alkali to give a pH of at least about 9.0.

No references cited.

NORMAN G. TORCHIN, Primary Examiner. 

14. A PROCESS FOR FORMING A VISIBLE PHOTOGRAPHIC IMAGE COMPRISING DEVELOPING A PHOTOEXPOSED PHOTOGRAPHIC ELEMENT COMPRISING A SUPPORT AND A PHOTOGRAPHIC SILVER HALIDE EMULSION LAYER, AND INTEGRAL WITH SAID PHOTOGRAPHIC ELEMENT, A WATER-PERMEABLE HYDROPHILIC COLLOID LAYER CONTAINING AN ACYL COMPOUND REPRESENTED BY THE FOLLOWING GENERAL FORMULA: 